<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>按从大到小排序</title>
</head>
<body>
    <script>
        var arr = [70, 67, 49, 35, 59, 98, 100, 20];
        for (var i = 0; i < arr.length - 1; i++) {
            for (var j = 0; j < arr.length - 1 - i; j++) {
                if (arr[j] < arr[j + 1]) {
                    var temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                }
            }
        }
        alert(arr);
    </script>
</body>
</html>